Some conventional radio paging receivers have a display function that a message signal to be transmitted following a receiver's own calling number is decoded and then displayed on its display, as well as a notifying function to notify a calling by a sound.
For example, Japanese patent application laid-open No. 5-199163 (1993) discloses a radio paging receiver with a display function to display a message composed of digits of 0 to 9 and some symbols. When a telephone number, e.g., 012-345-6789, is transmitted as a message, hyphens "-" can be inserted between positions predetermined by the receiver even when message signals corresponding to the hyphens "-" after "2" and "5".
Recently, a free word-displaying type radio paging receiver to display a message composed combining digits of 0 to 9, some symbols and Kana-letters (Japanese letters) is also developed. To such a radio paging receiver, a schedule message composed of time information and Kana information can be easily transmitted from an ordinary telephone terminal. For example, Japanese patent application laid-open No. 4-304039 (1992) discloses a free word-displaying type radio paging receiver to which a message composed of Kana letters and further Chinese characters can be transmitted. When a schedule message composed of date information enclosed by "[" and "]" and other information, e.g., "[Z24 /1800] Christmas Party in Yokohama" is transmitted, this radio paging receiver can identify the information as date information "December 24.sup.th 18:00" and can store the schedule message in its own storage, whereby it can be also used as an electronic notebook. Such a free word-displaying type radio paging receiver is in wide use since the advantage of radio paging receiver can be well utilized.
However, there are some problems in the conventional radio paging receiver. The first problem is that the operation is so complicated that one may make an operation error when inputting such a schedule message from a telephone terminal. Namely, for example, when transmitting a schedule message that a meeting is held at 15:00 of January 31.sup.st, the format is to input digits for the month, day, hour and minute between codes "[" and "]" followed by Kana information; "[01-31-15-00]{character pullout}". To divide the digits into the month, day, hour and minute, one has to input signals corresponding to "-(hyphens)" after "01", "31" and "15". When inputting it from a telephone terminal, for example, "*2" corresponding to "-" needs to be input.
The second problem is that the airtime is increased by that much. In the above example, the header (date and time display part) of the schedule message, "[01-31-15-00]{character pullout}" is "[01-31-15-00]". When representing this by using only the codes "[" and "]" and digits, the header is transmitted as "[01311500]". Thus, as the schedule message, 14 codes, "[01311500]{character pullout}" is transmitted. In the FLEX system mentioned above, information is transmitted using unit words, each word consisting of 32 bits of which 21 bits are information bits. The schedule message includes 56 bits because one code needs 4 bits. Thus, for the schedule message, the data transmission needs three words. Now, when three codes of "-(hyphen) " are added thereto, the data transmission needs four words because it includes 68 bits, adding 12 bits. In fact, the number of bits to be increased is by 21 bits, therefore the airtime must be increased.
The third problem is that, when transmitting the schedule message without adding the codes "-" in the above example, the receiver's owner cannot easily reads it because the received message is displayed without the codes "-", whereas the sender can easily conduct the inputting and the airtime can be reduced.
The fourth problem is that, when displaying the received schedule message on the display with having the three codes of "-", the number of codes to be displayed on the Kana display part is reduced by three codes, therefore Kana information is reduced.